Re: [PATCH] powerpc/32: Preserve cr1 in exception prolog stack check to fix build error

On Mon, 8 Feb 2021 07:17:40 + (UTC), Christophe Leroy wrote: > THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1 > Maximum PAGE_SHIFT is 18 for 256k pages so > THREAD_ALIGN_SHIFT is 19 at the maximum. > > No need to clobber cr1, it can be preserved when moving r1 > into CR when we check

[PATCH] powerpc/32: Preserve cr1 in exception prolog stack check to fix build error

THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1 Maximum PAGE_SHIFT is 18 for 256k pages so THREAD_ALIGN_SHIFT is 19 at the maximum. No need to clobber cr1, it can be preserved when moving r1 into CR when we check stack overflow. This reduces the number of instructions in Machine Check